The mantle and fireplace surround in a house my parents purchased need to be
re-worked. The wood portion is fine, but the previous owner used a light
green cultured marble inlay and hearth which needs to be replaced. The
material is 3/4" thick and creates a 6" or so trim band around the outside
of the fireplace opening, and the hearth extends 20" or out from the
fireplace. None of the material is located inside the firebox. The
brick/mortar fireplace has been converted to gas logs.

Anyway, I have noticed that the current cultured marble has bowed, either
due to continued curing (after all, it is a polyester resin, isn't it?), or
due to heat.

Which brings me to the real question... What is an appropriate material to
replace this cultured marble? Will *real* marble work? What are the odds
that new cultured marble would bow, assuming I could find some that was
attractive?

Any other materials to consider?

Thanks in advance.

KB

Does the green marble there now need to be replaced cause it's ugly, or
what ? "Cultured marble is made of approximately 75% crushed and
ground white quarried marble and 25% polyester resin."

I would go with some other (masonry) item. Here everyone seems to have
tile of some sort. I've never done a hearth thing, I presume tile
stuck on with glue is a no-go due to potential heat. Last house had
tiles set in some sort of cement mixture.